1. Field of the Invention
The present invention relates to a gear selection position displaying device for use with a gearshift system of an automatic transmission and a vehicle equipped with the gear selection position displaying device. More particularly, the present invention relates to a gear selection position displaying device which can preferably be applied to a gearshift system which has a home position and a holding position for a gearshift lever, whereby when the gearshift lever is shifted to the holding position from the home position, the gearshift lever is returned to the home position in the event that a predetermined condition is satisfied.
2. Description of the Background Art
In recent years, as gearshift systems for automatic transmissions installed on motor vehicles, so-called shift-by-wire type gearshift systems attract attention which are advantageous in reduction in operating force as well as size of gearshift systems. In the shift-by-wire method, the gear selection position of a gearshift system is detected by a sensor or the like so that gear ranges of an automatic transmission are changed over by an actuator based on a detection signal. Namely, in the shift-by-wire method, since the gear ranges of the automatic transmission are made to be changed over through electric controls, the degree of freedom in designing operation modes of a gearshift lever is increased. For example, a so-called momentary function can be imparted in which when the driver removes his or her hand from the gearshift lever which has been shifted into a predetermined gear selection position, the gearshift lever is automatically restored to a home position.
Here, as an example of common selection gear ranges in an automatic transmission, there are raised neutral gear range, drive gear range, reverse gear range and low-drive gear range (low-gear). (Note that a park gear range is a gear range where the automatic transmission is locked, and hence, the park gear range is different from the selection gear ranges in the automatic transmission.) In this case, to match these selection gear ranges, formed in a gearshift system are such gear selection positions as neutral position, drive position, reverse position and low-gear position. In the shift-by-wire type gearshift systems, the momentary function can be provided for all the gear selection positions, whereby since the gearshift lever can be positioned in the same position at all times except when the gearshift lever is operated, improvement in operability of the gearshift lever in gearshift can be expected.
For example, in Japanese Patent Unexamined Publication No. JP-A-2002-264684, a gearshift system is disclosed in which when the driver removes his or her hand from the gearshift lever which has been shifted into a predetermined gear selection position, the gearshift lever is automatically restored to the home position. In the event of the gearshift system like this, when the driver removes his or her hands from the gearshift lever after he or she has operated the lever, a state occurs at all times in which the gearshift lever is returned to the home position. When the gearshift lever is constructed so as to be located in the same position like this, there is caused a problem where the driver has difficulty in realizing the current gear range which is currently selected in the automatic transmission.
To solve this problem, in Japanese Patent Unexamined Publication No. JP-A-2003-327002, a gearshift system is described in which a holding function to hold a gearshift lever is provided for reverse position and low-gear position of gear selection positions, while at the other gear selection positions, the gearshift lever is automatically restored to the home position. According to the gearshift system like this, the driver can confirm the current gear range in the automatic transmission from the sensation in the hand, thereby making it possible to realize a gearshift system which has superior operability.
Incidentally, in the gearshift system having the gearshift lever holding function which is described in JP-A-2003-327002, when the gearshift lever is in the home position, the gear range in the automatic transmission is in a manual mode where the gears in the automatic transmission are changed over through a gearshift operation by the driver. This leads to a problem where the driver cannot make sure which gear is actually selected in the automatic transmission from the gear selection position, either. To cope with this, a technology is disclosed in JP-A-2002-264684 in which the gear range that is currently selected in the automatic transmission is displayed by highlighting with emitted light of a symbol or number (for example, “R” for reverse gear range, “L” for low-gear gear range, “3” for third gear, and the like) within the instrument cluster.
In the event that the emitted light highlighted display like this is applied to the gearshift system described in JP-A-2003-327002, however, since the actual shift lever position in the gearshift system cannot be displayed in a corresponding fashion, the driver needs to look at and comprehend the display. This leading to a problem where a certain length of time is necessary to confirm the currently selected gear range and a sensation of physical disorder is generated.
In addition, in a vehicle equipped with an automatic transmission, for example, when the driver selects the reverse position in the gearshift system while the vehicle is running forwards at a predetermined speed, there occurs a case where an automatic transmission control unit, which controls the changeover of gear ranges in the automatic transmission, determines invalid the gearshift operation effected by the driver and the control unit prohibits the changeover of gear ranges. However there has been no means for allowing the driver to recognize in advance that the gearshift operation done by him or her has been overridden.